I'm that friend of Sucky's that he's talking about...
For real though, what Sucky's saying is true; the more you learn the maps and especially where the power-ups are, your experience will improve a lot.
Strategic use of your secondary (chaff, heat sink, shield cell bank, and the other modules that unlock at higher ranks) is VERY important, and each of those modules have their own way they should be used. A LOT of the people I've popped in CQC never use them, which makes them even easier targets!
Another thing to really take advantage of, is your thrusters. USE your thrusters! Thrust up, down, left, right, reverse, and in different combinations so that you can get out of your enemy's firing arc and/or strafe around them. This is something that I use heavily, and it especially helps if they are using a projectile weapon because the more erratic your 'flight vector' or what ever is, the harder it will be for them to hit you with projectiles.
So using chaff/heatsinks and thrusting around like a maniac is what works for me, it could work for you too. Unless people are teaming and ganging up on you in free for all death-match(this happens a lot), then when the match is over just back out of it and try to get into a different group.